Law enforcement people have found shotguns to be useful for certain applications, such as blasting door locks, windows and even walls to gain entry into a structure in the course of their work. An officer's standard rifle, such as the AR-15 or M-16, could not efficiently do what a shotgun can do. Thus, a dedicated shotgun is typically carried, in addition to the usual rifle, if use of a shotgun is expected in a situation.
There is, therefore, a need to add the capability of a shotgun to an existing rifle to save the officer from carrying two long barrel guns. However, for the shotgun to be useful, it should be lightweight and should weigh less than the combined weight of the two individuals firearms. Additionally, the shotgun should have safety features and ease of use comparable to the standard rifle.
In a single shot firearm, the bolt is typically pulled back to discharge the spent cartridge and load a new cartridge, and pushed back to place the cartridge in the firing chamber and lock the bolt. However, the motions of pulling back and pushing forward are not simple straight line motions. For example, to unlock the bolt, one may have to lift the bolt handle before one can pull it back. In some guns, the motions could be more complicated.
There is, therefore, a need for single shot firearm where a simple straight line motion of pulling or pushing the bolt handle to eject or load a cartridge also unlocks or locks the bolt at the same time.
When a standard shotgun is used to break down a door lock, the end of the barrel is typically placed some distance from the target, to avoid damage to the barrel from flying debris or deflected pellets. If the shotgun is equipped with a stand-off device, the shotgun barrel can rest directly on the target, since the stand-off device will contain any deflected debris or shots. Since not every situation will require a stand-off device, provisions should be provided to allow its quick removal without too much inconvenience.
There is, therefore, a need for a shotgun equipped with a stand-off device that can be easily and quickly deployed or removed as needed.
Since the shotgun is mounted to a main rifle, it is desirable to be able to use the main rifle's sight for shotgun. To do this, the mounting assemblies for the shotgun should have adjustments to orient the shotgun in relation to the sight.
There is, therefore, a need for mounting assemblies used to secure a shotgun to a main rifle to have adjustment capabilities, such as for range adjustment, so the main rifle's sight can also be used for the shotgun.
Safety of use is always a concern to the user. Prior art firearms are equipped with safety devices that are actuated with small levers, which are hard to see. Thus, one has to look hard or feel its position to determine whether the safety device is on or not. It is, therefore, desirable for a firearm to have adequate and dependable safety features that are easy to use and easy to see whether it is ON or OFF.
In severe cold weather conditions, a user could be wearing heavy gloves while being required to operate a firearm. Where the trigger guard is fixed and immovable, the user's gloved index finger may not fit into the space of the trigger. A trigger guard that can swing out of the way to provide additional finger room at the trigger is, therefore, desirable.
Since an auxiliary gun, such as a shotgun, mounted to a main rifle would not be expected to be used most of the time, it should be as unobtrusive as possible to the user whenever it is not being used. The bolt handle is one part of the gun that can get in the way. It is, therefore, desirable that the bolt handle be provided such that it can be moved out of the way when the shotgun is not being used. Further, since the shotgun can be used by either a left or right-handed person, the bolt handle should be ambidextrous.